Radio receiving system



H. K. SANDELL RADIO RECEIVING SYSTEM Feb. 12 1924.

Filed Nov. 2. 1922 2 Sheets-Sheet 1 3 2 6727? ff $0702 8]; gW d ZZ jd 2 Sheets-Sheet 2 H. K. SANDELL RADIO RECEIVING SYSTEM Filed Nov. 2, 1922 Feb. 12 1924;

Patented eb. 12, 1924.

UNITED STATES PATENT OFFICE.

HENRY K. SANDELL, OF CHICAGO, ILLINOIS, ASSIGNOR TO MILLS NOVELTY COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION 01! ILLINOIS.

RADIO, RECEIVING SYSTEM.

Application filed November 2, 1922. Serial No. 598,553.

To all whom it may concern:

Be it known that I, HENRY K. SaNoanL, a citizen of the United States, residin at Chicago, in the county of Cook and tate I of Illinois, have invented a new and useful Improvement in Radio Receiving Systems, of which the following is a specification.

The present invention relates to improvements in radio receiving systems and will 10 be fully understoodfrom the following description illustrated by the accompanying drawings, in which- Figure 1 is a perspective view of the loop aerial and the plate circuit loop, together ll with their mounting.

Figure 2 is aplan' view of a condenser mfolli pting used in connection with the device i 1.

Fi re 3 is a sectional view on the line in 3-3 of Fig. 2.

Fi re4 is a diagrammatic view illustrating t e circuits employed in accordance with the present invention.

In the drawings the numeral 5 indicates I a loop or spiral aerial, preferably with its coils in a single plane. It is connected at one end through the condenser 6 with the grid 7 of a vacuum tube or audion 8-. From any selected point on the aerial 5 a con- I0 nection may be made by the clip 9 and flexible conductor 10 with the connector 11 leading to the grounded connector 12". A filament heating circuit 12 including the connector 12, the battery 13, the variable.

86 resistance 14, and the connector 12" is rovided for filament 15 of the audion 8. he loop aerial 5 is mounted upon a suitable cross 16, the arms of which are formed of members of equal width. The coils of the aerial 5 are inserted in slots 17 formed in the edges thereof. In the opposite edges of the arms of the cross mounting 16 are simi larly inserted the coils of a second loop or spiral 18, which are thus maintained parallel to and spaced from the coils-of the aerial 5. The loop or spiral 18 is connected at one and through a connector 19 to the filament 15 of the audion 8. From a selected point on the loop or spiral 18, connection is made through a clip 20, flexible connector 21, connector 21', variometer 23, receiver 24, battery 25 and connector 21' with the plate 22 of the audion 8. From the aerial 5, connection, is made through a conductor 26, a variable condenser 27 and a conductor 28 to the coil 18. As illustrated in the drawings, the condenser 27 ma suitably be mounted on one of the arms of t e cross 16 which serves as a mounting for the two loops. A slot 29 may be cut angularly in the arm of the cross 16 and a condenser plate 30 of generally semi-circular shape is secured to the end of the actuating shaft 31 so as to be movable in the slot 29. The shaft 31 is journalled in a suitable bearing 32 secured to the arm of the cross 16, the shaft being likewise provided with a knurled head 33 for convenience in operation. The other condenser plate 34, which may likewise be of semi-circular shape, is mounted on the arm of the cross 16 adjacent the slot 29, the movement of the condenser plate 30 varyin' the capacity of the condenser.

n the form of construction shown, both loops are conveniently mounted in proper spaced relation and in parallelism upon the cross 16. The condenser 27 and the audion 8 are. likewise mounted on this cross. The battery 13 and resistance for the control of the filament circuit and the variometer 23, receiver 24 and battery 25 connected in the plate circuit are removed to a suitable point for the remote control of the set. The connectors 12 and 12 are brought to the remote control point in a single cable, as are the plate circuit connectors 18 and 21. This is indicated in the construction illustrated in Fig. 1. It is found that by carrying these connectors in single cables in the manner set forth, an improvement in sensi-' tiveness and clearness of reception results.

In controllin the operation of the system, the clip 9 is attached to the aerial 5 at the proper coil to produce the best results t for the wave length to be received. The" position of the clip 20 on the coils of the loop 18 may then be varied as may also the capacity 27 and the variometer 23, to secure the desired results in the reception of the signals transmitted.

I claim:

1. In a radio receiving system, a vacuum tube, a loop'aerial connected to the grid of said tube, a loop in series with the plate and filament of said tube, said aerial and loop having their planes paralle and spaced from each other, a connection between the loop aerial and the loop, and a condenser interposed in said connection.

2. In a radio receiving system, 9, vacuum 110 tube, a loop aerial connected with the grid of the tube, a second loop in series in the plate circuit of said tube, said loop aerial and second loop being inductively related to each other, a connection between the loop aerial and the second loop and a variable condenser interposed in said connection.

3. In a radio receiving system, a support having crossed arms, a 100 aerial secured said arms on one side 0" said support, a second loop secured to said arms on the opposite side of said sup ort, a vacuum tube, means for connecting t e loop aerial with the grid of said tube, and means for connecting the second loop with the plate of said tube.

' 4. In a radio receiving system, a support having crossed arms, a loop aerial secured to said arms on one side "oisaid support, a second loop secured to said arms on the opposite side or said support, a condenser secured to said support, connectors from the condenser to the loop aerial and the second loop, a;vacuum tube, means for connecting the loop aerial with the grid of said tube, and means for connecting the second loop with the plate of said tube.

5. In a radio receiving system, a loop aerial and a second loop in inductive relationship, a vacuum tube, means connecting the loop aerial with. the grid of said tube, remote control devices for the filament of the tube, conductors from the tube to said control devices, said conductors being united in a single cable, remote control devices for the plate circuit of the tube, and separate conductors between the plate of the tube and said control devices and between the second loop and said control devices, said conductors being united in a single cable.

HENRY K. SANDELL. 

